TRIM proteins in neuroblastoma

TRIM54 alleviates inflammation and apoptosis by stabilizing YOD1 in rat tendon-derived stem cells

Tendinopathy is a disorder of musculoskeletal system that primarily affects athletes and the elderly. Current treatment options are generally comprised of various exercise and loading programs, therapeutic modalities, and surgical interventions and are limited to pain management. This study is to understand the role of TRIM54 (tripartite motif containing 54) in tendonitis through in vitro modeling with tendon-derived stem cells (TDSCs) and in vivo using rat tendon injury model. Initially, we observed that TRIM54 overexpression in TDSCs model increased stemness and decreased apoptosis. Additionally, it rescued cells from tumor necrosis factor α-induced inflammation, migration, and tenogenic differentiation. Further, through immunoprecipitation studies, we identified that TRIM54 regulates inflammation in TDSCs by binding to and ubiquitinating YOD1. Further, overexpression of TRIM54 improved the histopathological score of tendon injury as well as the failure load, stiffness, and young modulus in vivo. These results indicated that TRIM54 played a critical role in reducing the effects of tendon injury. Consequently, these results shed light on potential therapeutic alternatives for treating tendinopathy.

TRIM25-mediated ubiquitination of G3BP1 regulates the proliferation and migration of human neuroblastoma cells

Neuroblastoma is one of the most severe malignant tumors and accounts for substantial cancer-related mortality in children. Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is highly expressed in various cancers and acts as an important biomarker of poor prognosis. The ablation of G3BP1 inhibited the proliferation and migration of human SHSY5Y cells. Because of its important role in neuroblastoma, the regulation of G3BP1 protein homeostasis was probed. TRIM25, which belongs to the tripartite motif (TRIM) family of proteins, was identified as an interacting partner for G3BP1 using the yeast two-hybrid (Y2H) method. TRIM25 mediates the ubiquitination of G3BP1 at multiple sites and stabilizes its protein level. Then, our study found that TRIM25 knockdown also inhibited the proliferation and migration of neuroblastoma cells. The TRIM25 and G3BP1 double knockdown SHSY5Y cell line was generated, and double knockdown cells exhibited lower proliferation and migration ability than cells with only TRIM25 or G3BP1 knockdown. Further study demonstrated that TRIM25 promotes the proliferation and migration of neuroblastoma cells in a G3BP1-dependent manner. Tumor xenograft assays indicated that the ablation of TRIM25 and G3BP1 synergistically suppressed the tumorigenicity of neuroblastoma cells in nude mice, and TRIM25 promoted the tumorigenicity of G3BP1 intact SHSY5Y cells but not G3BP1 knockout cells. Thus, TRIM25 and G3BP1, two oncogenic genes, are suggested as potential therapeutic targets for neuroblastoma.

Ubiquitination and degradation of MGMT by TRIM72 increases the sensitivity of uveal melanoma cells to Dacarbazine treatment

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults with high metastasis rates. The O6-methylguanine DNA methyl transferase (MGMT) is involved in chemoresistance of Dacarbazine (DTIC) treatment. Our previous study found that the combination of oncolytic adenovirus H101 and DTIC in the treatment of UM cells shows a synergistic antitumor effect mainly though down-regulation of MGMT. MGMT knockdown by shRNAs increases the sensitivity of uveal melanoma cells to DTIC treatment. The protein hemostasis of MGMT is important for the antitumor effect of DTIC. Tripartite motif-containing protein 72 (TRIM72) belongs to the tripartite motif (TRIM) proteins family and was identified as a novel E3 ligase for MGMT, which interacts with and mediates the ubiquitination of MGMT. TRIM72 knockdown increases the protein levels of MGMT, while reduces the ubiquitination of MGMT. Further study indicated that MGMT is highly expressed in UM cells, and the protein levels of MGMT and TRIM72 shows a negative correlation. UM cells that ectopically expressing TRIM72 shows increased sensitivity to DTIC treatment, which is consistent with the antitumor affect exhibited by H101. These results suggest that TRIM72 is a promising therapeutic target for UM treatment.

A Promising Intracellular Protein-Degradation Strategy: TRIMbody-Away Technique Based on Nanobody Fragment

Most recently, a technology termed TRIM-Away has allowed acute and rapid destruction of endogenous target proteins in cultured cells using specific antibodies and endogenous/exogenous tripartite motif 21 (TRIM21). However, the relatively large size of the full-size mAbs (150 kDa) results in correspondingly low tissue penetration and inaccessibility of some sterically hindered epitopes, which limits the target protein degradation. In addition, exogenous introduction of TRIM21 may cause side effects for treated cells. To tackle these limitations, we sought to replace full-size mAbs with the smaller format of antibodies, a nanobody (VHH, 15 kDa), and construct a new type of fusion protein named TRIMbody by fusing the nanobody and RBCC motif of TRIM21. Next, we introduced enhanced green fluorescent protein (EGFP) as a model substrate and generated αEGFP TRIMbody using a bispecific anti-EGFP (αEGFP) nanobody. Remarkably, inducible expression of αEGFP TRIMbody could specifically degrade intracellular EGFP in HEK293T cells in a time-dependent manner. By treating cells with inhibitors, we found that intracellular EGFP degradation by αEGFP TRIMbody relies on both ubiquitin-proteasome and autophagy-lysosome pathways. Taken together, these results suggested that TRIMbody-Away technology could be utilized to specifically degrade intracellular protein and could expand the potential applications of degrader technologies.

The TRIM proteins in cancer: from expression to emerging regulatory mechanisms

New clinical evidence suggests that dysregulation of the ubiquitin-mediated destruction of tumor suppressors or oncogene products is probably engaged in the etiology of leukemia and carcinoma. The superfamily of tripartite motif (TRIM)-containing protein family is among the biggest recognized single protein RING finger E3 ubiquitin ligases that are considered vital carcinogenesis regulators, which is not shocking since TRIM proteins are engaged in various biological processes, including cell growth, development, and differentiation; hence, TRIM proteins' alterations may influence apoptosis, cell proliferation, and transcriptional regulation. In this review article, the various mechanisms through which TRIM proteins exert their role in the most prevalent malignancies including lung, prostate, colorectal, liver, breast, brain cancer, and leukemia are summarized.

Ubiquitination of p21 by E3 Ligase TRIM21 Promotes the Proliferation of Human Neuroblastoma Cells

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood, which shows great clinical and biomolecule heterogeneity. Currently, surgery is still the main method of neuroblastoma treatment and specific therapeutic drugs are lacking, so useful targets are urgently needed. TRIM21 is a RING-type E3 ligase that its overexpression promotes the progression of human glioma, while whose effects on neuroblastoma have not been illustrated. Firstly, the shRNAs targeting TRIM21 were designed and found that the ablation of TRIM21 inhibits the proliferation of human neuroblastoma cells. Then the molecular mechanism study indicated that TRIM21 interacts with, and mediates p21 degradation by ubiquitination modification. Further study demonstrates that TRIM21 regulates the proliferation of neuroblastoma cells in a p21-dependent manner. These results suggest that TRIM21 might be a potential therapeutic target for neuroblastoma.

Blockade of TRIM59 enhances esophageal cancer cell chemosensitivity to cisplatin by upregulating p53

Human esophageal cancer (hESC) cell motility adopts various modes, resulting in hESC progression and poor survival. However, how tripartite motif 59 (TRIM59), as the ubiquitination machinery, participates in hESC metastasis is not completely understood. The results indicated that TRIM59 was aberrantly upregulated in hESC tissues compared with adjacent healthy esophageal tissues, which was associated with poor survival and advanced TNM state among patients with hESC. Moreover, patients with hESC with higher TRIM59 expression displayed undetectable p53 expression, which contributed to enhanced progression and motility of hESC. At the molecular level, TRIM59 was indicated to be an E3 putative ubiquitin ligase that targeted the p53 protein, leading to increased degradation of p53, which resulted in decreased chemosensitivity to cisplatin. TRIM59 knockdown reduced TRIM59 expression, increased p53 protein expression, and decreased hESC cell viability, clone formation and migration compared with the small interfering RNA negative control (siNC) group. Furthermore, hESC cell lines were more sensitive to cisplatin in the TRIM59-knockdown group compared with the siNC group. The results indicated a relationship between TRIM59, p53 and the chemosensitivity of cisplatin. The present study suggested that TRIM59 may serve as a promising prognostic indicator for patients with hESC.